Plus Comments is a Chrome extension by Jim Blackler, that when installed shows public comments on Google+ about the pages you browse to.
How it works
The extension uses a secure (https) link to the Google+ API and services directly, to make queries which include some or all of the URLs of the pages you visit. There is no other server component.
The app is designed to exclude personal or sensitive information from URLs. It does not request data about URLs of secure sites (https), URLs that look like intranet (internal organization) URLs, or any URL parameters other than known page identifiers (such as YouTube video IDs).
Google+ credentials are not required or used. The app does not record user identity or activity in any way. The app does not store any data at all between sessions.